/* $OpenBSD: ieee80211_radiotap.h,v 1.8 2006/06/23 21:34:15 reyk Exp $ */ /* $FreeBSD: src/sys/net80211/ieee80211_radiotap.h,v 1.3 2004/04/05 22:13:21 sam Exp $ */ /* $NetBSD: ieee80211_radiotap.h,v 1.9 2004/06/06 04:13:28 dyoung Exp $ */ /*- * Copyright (c) 2003, 2004 David Young. All rights reserved. * * Redistribution and use in source and binary forms, with or without * modification, are permitted provided that the following conditions * are met: * 1. Redistributions of source code must retain the above copyright * notice, this list of conditions and the following disclaimer. * 2. Redistributions in binary form must reproduce the above copyright * notice, this list of conditions and the following disclaimer in the * documentation and/or other materials provided with the distribution. * 3. The name of David Young may not be used to endorse or promote * products derived from this software without specific prior * written permission. * * THIS SOFTWARE IS PROVIDED BY DAVID YOUNG ``AS IS'' AND ANY * EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, * THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A * PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL DAVID * YOUNG BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, * EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED * TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND * ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, * OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY * OF SUCH DAMAGE. */ #ifndef _NET_IF_IEEE80211RADIOTAP_H_ #define _NET_IF_IEEE80211RADIOTAP_H_ /* A generic radio capture format is desirable. There is one for * Linux, but it is neither rigidly defined (there were not even * units given for some fields) nor easily extensible. * * I suggest the following extensible radio capture format. It is * based on a bitmap indicating which fields are present. * * I am trying to describe precisely what the application programmer * should expect in the following, and for that reason I tell the * units and origin of each measurement (where it applies), or else I * use sufficiently weaselly language ("is a monotonically nondecreasing * function of...") that I cannot set false expectations for lawyerly * readers. */ /* XXX tcpdump/libpcap do not tolerate variable-length headers, * yet, so we pad every radiotap header to 64 bytes. Ugh. */ #define IEEE80211_RADIOTAP_HDRLEN 64 /* The radio capture header precedes the 802.11 header. */ struct ieee80211_radiotap_header { u_int8_t it_version; /* Version 0. Only increases * for drastic changes, * introduction of compatible * new fields does not count. */ u_int8_t it_pad; u_int16_t it_len; /* length of the whole * header in bytes, including * it_version, it_pad, * it_len, and data fields. */ u_int32_t it_present; /* A bitmap telling which * fields are present. Set bit 31 * (0x80000000) to extend the * bitmap by another 32 bits. * Additional extensions are made * by setting bit 31. */ } __packed; /* Name Data type Units * ---- --------- ----- * * IEEE80211_RADIOTAP_TSFT u_int64_t microseconds * * Value in microseconds of the MAC's 64-bit 802.11 Time * Synchronization Function timer when the first bit of the * MPDU arrived at the MAC. For received frames, only. * * IEEE80211_RADIOTAP_CHANNEL 2 x u_int16_t MHz, bitmap * * Tx/Rx frequency in MHz, followed by flags (see below). * * IEEE80211_RADIOTAP_FHSS u_int16_t see below * * For frequency-hopping radios, the hop set (first byte) * and pattern (second byte). * * IEEE80211_RADIOTAP_RATE u_int8_t 500kb/s * * Tx/Rx data rate * * IEEE80211_RADIOTAP_DBM_ANTSIGNAL int8_t decibels from * one milliwatt (dBm) * * RF signal power at the antenna, decibel difference from * one milliwatt. * * IEEE80211_RADIOTAP_DBM_ANTNOISE int8_t decibels from * one milliwatt (dBm) * * RF noise power at the antenna, decibel difference from one * milliwatt. * * IEEE80211_RADIOTAP_DB_ANTSIGNAL u_int8_t decibel (dB) * * RF signal power at the antenna, decibel difference from an * arbitrary, fixed reference. * * IEEE80211_RADIOTAP_DB_ANTNOISE u_int8_t decibel (dB) * * RF noise power at the antenna, decibel difference from an * arbitrary, fixed reference point. * * IEEE80211_RADIOTAP_BARKER_CODE_LOCK u_int16_t unitless * * Quality of Barker code lock. Unitless. Monotonically * nondecreasing with "better" lock strength. Called "Signal * Quality" in datasheets. (Is there a standard way to measure * this?) * * IEEE80211_RADIOTAP_TX_ATTENUATION u_int16_t unitless * * Transmit power expressed as unitless distance from max * power set at factory calibration. 0 is max power. * Monotonically nondecreasing with lower power levels. * * IEEE80211_RADIOTAP_DB_TX_ATTENUATION u_int16_t decibels (dB) * * Transmit power expressed as decibel distance from max power * set at factory calibration. 0 is max power. Monotonically * nondecreasing with lower power levels. * * IEEE80211_RADIOTAP_DBM_TX_POWER int8_t decibels from * one milliwatt (dBm) * * Transmit power expressed as dBm (decibels from a 1 milliwatt * reference). This is the absolute power level measured at * the antenna port. * * IEEE80211_RADIOTAP_FLAGS u_int8_t bitmap * * Properties of transmitted and received frames. See flags * defined below. * * IEEE80211_RADIOTAP_ANTENNA u_int8_t antenna index * * Unitless indication of the Rx/Tx antenna for this packet. * The first antenna is antenna 0. * * IEEE80211_RADIOTAP_FCS u_int32_t data * * FCS from frame in network byte order. * * IEEE80211_RADIOTAP_HWQUEUE u_int8_t data * * A specific hardware queue (used by WME) * * IEEE80211_RADIOTAP_RSSI 2x u_int8_t RSSI, max RSSI * * A relative Received Signal Strength Index */ enum ieee80211_radiotap_type { IEEE80211_RADIOTAP_TSFT = 0, IEEE80211_RADIOTAP_FLAGS = 1, IEEE80211_RADIOTAP_RATE = 2, IEEE80211_RADIOTAP_CHANNEL = 3, IEEE80211_RADIOTAP_FHSS = 4, IEEE80211_RADIOTAP_DBM_ANTSIGNAL = 5, IEEE80211_RADIOTAP_DBM_ANTNOISE = 6, IEEE80211_RADIOTAP_LOCK_QUALITY = 7, IEEE80211_RADIOTAP_TX_ATTENUATION = 8, IEEE80211_RADIOTAP_DB_TX_ATTENUATION = 9, IEEE80211_RADIOTAP_DBM_TX_POWER = 10, IEEE80211_RADIOTAP_ANTENNA = 11, IEEE80211_RADIOTAP_DB_ANTSIGNAL = 12, IEEE80211_RADIOTAP_DB_ANTNOISE = 13, IEEE80211_RADIOTAP_FCS = 14, IEEE80211_RADIOTAP_HWQUEUE = 15, IEEE80211_RADIOTAP_RSSI = 16, IEEE80211_RADIOTAP_EXT = 31 }; /* For IEEE80211_RADIOTAP_FLAGS */ #define IEEE80211_RADIOTAP_F_CFP 0x01 /* sent/received * during CFP */ #define IEEE80211_RADIOTAP_F_SHORTPRE 0x02 /* sent/received * with short * preamble */ #define IEEE80211_RADIOTAP_F_WEP 0x04 /* sent/received * with WEP encryption */ #define IEEE80211_RADIOTAP_F_FRAG 0x08 /* sent/received * with fragmentation */ #endif /* _NET_IF_IEEE80211RADIOTAP_H_ */